Variable-load brake



Aug. ze.. 1924.

J. c. MccuNE VARIABLE LOAD BRAKE Filed Oct. 19. 1923 g y ymmms INVENTORy JOSEPH @.MCCUNE ATTORN EY Patented Aug. 26, 1924.

UNITED STATES PATENT OFFICE;

JOSEPH C. MCCUNE, OF ORANGE, NEW JERSEY, ASSIGNOR TO THE WESTINGHOUSEAIR BRAKE COMPANY, 0F WILMERDING, PENNSYLVANIA, A CORPORATON OF iPENNSYLVANIA.

VARIABLE-LOAD BRAKE.

Application filed October 19, 1923.

To all whom it may concern:

Be it known that I, JOSEPH C. MCCUNn, a citizen of the United States,residing at Orange, in the county of Essex and State of New Jersey, haveinvented new and useful Improvements in Variable-Load Brakes, of' whichthc `following is a specification.

This invention relates to fluid pressure brakes, and more particularlyto a brake equipment in which the braking power is regulated accordingto the load on the car.

rlhe principal objec-tol my invention is 'to provide a load brak-eequipment in which the operation is controlled by fluid under pressureemployed in operating the car doors.

In the accompanying drawing, the single figure is a diagrammatic view7partly in section, of a variable load brake equipment embodying myinvention.

As shoivn in the drawing, the equipment may comprise a brake Vcylinderpressure limiting, valve device 1, a locking mechanism 2, and a strutcylinder mechanism 3.

The valve device 1 may comprise a ilexible diaphragm 4, subject on oneside to pressure in thebrake cylinder 5, as supplied'trom chamber 6, andsubject on the opposite side to the pressure of an adjustable coilspring 7. The adjustment of spring 7 is eiliec-ted by the movement. ofav plunger S, the lower end of which is adapted to engage a plate 9which is carried by a sliding rod 10.

Pivot-ally mounted adjacent to plate 9 is a crank arm member havingcrank arms 11, 12, andl, the arm 1l being adapted to engage the lowerend 'ot the rod 10, The arm 1Qv is pivotally connected to a piston rod14 having a piston head 15 which is adapted to work in a cylinder 1G.The cylinder 1G is connected to a strut member 17 having its outer endpivotally connected to a bell crank lever 18. One arm of the bell crank18 is adapted to engage an operating member 19 which is carried by thecar truck, v

ivhile the bell crank is mounted on the car body, so that there is arelative movement bet-Ween the bell crank 18 and the member 19 accordingto the compression ot the car springs under load.

The crank arm 13 is connected through a link 2O ivi-th a ratchet bar 21,the teeth oi' which are engageable b v paivls Q2 and 23 carriedrespectively by pistons il and 25.

,the car.

Serial No. 669,491.

gine 29 for operating the door engine to ctliect the opening oft the.car door7 is counected to the piston 27 through a pipe BO.

lt' Athe equipment is applied to a double F cnd car having a doorcontrol valve 31 at each end of. the car, a double check valve device 32may be interposed between the door pipes 28 at each end of the car andthe variable load pipe 30. rThe device r32 con-- tains a double checkvalve adapted to cut oitq communication from the door control pipe 28 atone end of the car When fluid is supplied to the pipe` 2S at the otherend of l/Vith a single end equipment, it would not, of course, benecessary to provide a double check valve.

ln order to control the operation of pis-ton 15, a double beat valve 3stis provided which is adapted to be operated by a pis-k ton 35. Thepiston chamber 36 of said piston chamber of the. piston 25, so that whenlluid under pressure is supplied to pistons and it. is also supplied topiston ln operation, when a car equipped with the above describedapparatus is brought to a stop and a car door is opened. for example, bymanipulating the controlling valve 31 at the right ot the drawing, therotary valve 3T is turned by handle 3S, so that a port 39 establishescommunication for supplying fluid under pressure to pipe Thecorresponding door engine 29 is then operated to open the car door andat the same time Fluid is supplied to the double s. valve 3?), which isthen shifted to the le r, so as to establish communication from pipe 28,at: the rightrto pipe 30. Fluid supplied to pipe 30 operatesopiston 27and thereby the double beat valve Q6 so as to cut off comiminicationfrom a source of fluid ysupply 110 to pistons 2li and 25 and open ing ofthe car door.

operated lay-springs 4l aiifd soas tosliit the pawls 22 and 23 out ot'locking engagein ent with the teeth of the ratchet bai'Q-l andconsequently the bar 21 is no-wtree to move vertically.

lVlieii tluidiinder pressure is vented from pistons 24. and 25, it isalso vented iironipiston 35, so that. said piston will be shifted towardthe right, permittiiigtlie double beat valve 34 to move so that.communication from piston 15 to the atiirosplhere is .cutoff whi lecommunication is: established .from the reservoir 40 tliirougli passage43 and i'iexible hose 44 to piston 15. The admission of fluid underpressure to piston 1.5 causes movement of the cylinder 1G and rod17`toward the rig-ht and thereby the bell crank 18 is rotated so thatone arm engages the member 19.

It the load on the car is increased by 'passengers entering the car therelative vertical movement 'between the bell crank 18 and .the member 19produced by movement ot .the caibody relative to the car truck, willcause .a corresponding ,movement of the rod 17 'toward the left, but aspiston 15 is now maintained .at lits extreme lett hand position .byfluid pressure supplied Vto cylinder 16, this movement of rod 17toward'the 'left also effects a corresponding movement of the piston rod14,'sothat the crank arm 12 is rotated in a clockwise direction. Thecrank arm 11 is .thus `rotated in the same direction. vcausing .anupward vertical .movement of rod 10 and plate 9. The` upward movementoit plate 9 is transmitted to the plunger 8 which then operates 'tocompress ythe spring 7, so as to increasethe spring pressure ondiaphragm 4.

vIt the load on the car is reduced bypassengeis leaviiigtlie car, thebell crank 18'wi'll move iii a clockwise direction, so that the rod 17will move toward the right, causing a ii'iovement of piston rod 14towarditheiig'ht .and va coi-interclockwise Amovement of the crank arm12. The crank arm 11 is also i'olated in a cdunter-clockwise direction,so that rod 10 is, permitted to move downwardly and with it, the plate.9 and the plunger 8. The downward movement of the plunger 8 kthenreduces the compression of spring '7 and the spring pressure on'tlie.diaphragm 4.

Any ,movement of' the crank arm l2 also etle'cts a correspondingmovement of the .crank arm 13, so that ratchet bar '.21 is shiftedaccordingly. When the car is about t0 start, the car door is firstclosed by operating the kcontrolling-valve 31, `so as t0 connectpipe 28with exhaust port 45 and fluid under pressure is then released fromthedoor engine29, so that said engine .operates to effect the clos- At theSametime, fluid is vented from pipe 30 andthe 'face of piston 27, soAthat said piston is shifted to 4its outer position, as shown iii thedrawing. The

double beat valve v26 yis operated this movement ot the'piston so as tocut oit cominuni'cat'ion from pistons 24 and 25 to the atmosphereandopen communication from reservoir 40 to said pistons.

The pistons Q4 and '25 are then shifted toward :the left, causing thepawls 22 and 23 to engage the teeth 0i' the ratchet bar 21, s0 as tolock said lbai' iii its adjusted position and consequently the plunger 8is locked in its adjusted position kcorresponding with vthe 'loadonthecar.

Fluid is also 'supplied lto Apiston 35, so that said piston is shiftedJto its left lhand position, as shown in the drawing, the double'beatva'lve 3'4lbeing shifted, lso'that communication tromxt-hereservoir 40vto piston v15 is cut oil?, wlii-l'e communication isestablished A"from said piston to the atmosphere. Therelease o'f'lu-idtronicylinder 16 then perni-its spring tti-to retract the cylinder to'the 'position shown in the drawing, so that rod 17 shifts ,the bellcrank 18 out of engagement `with the member 19. It will thus be seen i'that while `the car is ruiming, -the adjusting'i mechanism is notaffected by any relative movement between the ear lbody and the cartruck.

t'tlie brakes yare applied, l'iL-luid under -pressure is supplied t0pipe-47 by the operation-0f `the usual apparat-us employed 'in effectingv4an application of :the brakes.` Fluid supplied to pipe 47 `flovvs:into chamber-48 and acts on thefeX-posed -area lof a valve piston-49,-so fas to cause said valve piston to lift from its'seat. Fluid is thensupplied tofchamber '-6 and lthenceto the brake cylinder 5. Fluidsupplied to chamber '6 also flows through passage 50 to the diaphragm 4and when 'the pressure inthe `brake cylinder has been increased lto apredetermined degree, corresponding with the 4previous adjust-ment ofthe spring 7 inthe manner liereiiiibe-fore described, tlie diaphragm 4will be shifted so as `to permit valve 51130 close. Any further increasein pressure 'in'chani'ber 48 'then acts on the spring side oiE valve'piston 49 -aiid since such increase in'pressure cannotequalize oii'the'valve pis'ton4'9, due 'to the closurew of vadve v51, said valve pistonA49 Ywill bei"w shifted to its seated position, cutting 0H 'the yfurthersupply of iluid to the brake cylinder.

Having now described Vmy inventiom, vwhat I claim as new and desiretese/cure by power .according to the 'load on the car, .of

liiuid pressure operated locking inechanisnr" for locking said means in'its ladjusted-position, a fluid `pressure operated mechanism torconnecting up said adgu-sting means'tor control,according to the load-on the cai, mea-ns including a zpiston `for coiitrolling'tlie' fluidpressure for operating said locking mechanism and said connectingmechanism, and fluid pressure means for controlling a car door, saidpiston being operated by fluid pressure supplied to said car doorcontrolling means.

2. In a variable load brake, the combination with means for adjustingthe braking power according to the load on the car, of liuid pressureoperated locking mechanism for locking said means in its adjustedposition including a piston, a fluid pressure operated mechanism foroperatively connecting said adjusting means so as to be controlled bythe load on the car, valve means for controlling the luid pressure foroperating said connecting mechanism, a piston for operating said valvemeans, valve means Jfor controlling the fluid pressure on both of theaforesaid pistons, and a piston for operating said valve means.

3. In a variable load brake, the combination with means for adjustingthe braking power according to the load on the car, of fluid pressureoperated locking mechanism Yfor locking said means in its adjustedposition including a piston, a iiuid pressure operated mechanism foroperatively connecting said adjusting means so as to be controlled bythe load on the car, valve means for controlling the fluid pressure foroperating said connecting mechanism, a piston for operating said valvemeans, valve means for controlling the fluid pressure on both of theaforesaid pistons, a piston for operating said valve means, and a doorengine operated by Varia-tions in fluid pressure for controlling a cardoor, the last mentioned piston being subject to and operated byVariations in fluid pressure on said door engine.

In testimony whereof I have hereunto set my hand.

JOSEPH C. MGCUNE.

